Age-differences in brain sensitivity and tolerance to ethanol in mice
The present study was designed to evaluate the effect of an acute injection of ethanol on the onset and the duration of the loss of righting response in mice of three different ages, 6, 12, and 24 months old. Measurements were made of the brain ethanol concentrations at the time the righting response was lost as an index of initial central nervous system sensitivity to ethanol. Brain ethanol levels were also measured at the time the righting response was regained. By comparing the difference between these levels and the levels at the time the response was lost, the ability to develop acute tolerance was determined. The rate at which ethanol appeared in the brain, as well and as the drug’s accumulation in and disappearance from the blood, was also measured to determine drug uptake and metabolism in the three age groups. The results indicate that old mice: are more sensitive to the central nervous system effects of ethanol, have a slower rate of ethanol uptake into both blood and brain, and metabolize ethanol more slowly than 6 and 12 month old mice. Twelve month old mice differ from 6 month old mice only in the rate at which ethanol is metabolized. All three groups of mice were equally capable of developing acute tolerance to ethanol.
KeywordsCentral Nervous System Ethanol Concentration Drug Uptake Ethanol Uptake System Sensitivity
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